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“This is your brain. This is your brain on drugs… any questions?” Scientists now are asking how public service announcements (PSAs) such as that powerful 1987 anti-drug ad affect the teenage brain. New research suggests that persuasive anti-drug ads activate both the emotional and executive functions of the teenage brain.

“There is a clear need for assessing the efficacy of anti-drug PSAs, especially as adolescent substance use continues to be a problem, and these types of PSA interventions are both expensive and at times ineffective,” says Ian Ramsay, a graduate student at the University of Minnesota. “Additionally, anti-drug messages are a useful tool for studying persuasion in general, as there is moderate variability among individuals’ beliefs about the negative consequences of illicit drug use.”

Therefore, Ramsay, working with colleagues under his adviser Angus MacDonald, decided to look at the adolescent brain under the influence of these anti-drug messages. They wanted to better understand the neural processes underpinning persuasion in the teen brain.

The research team scanned the brains of 70 adolescents, ages 15 to 19, using fMRI while they watched 30-second ads: either 10 strongly convincing anti-drug PSAs;10 weakly convincing anti-drug PSAs; or 10 ads unrelated to drugs. The ads unrelated to drugs were on topics associated with negative emotions such as violent video games and chewing gum so that the brain responses would be comparable those from the antidrug ads.

After watching the ads in the fMRI, the participants rewatched them, this time rating how strongly emotionally aroused they felt. That behavioral data allowed the researchers to account for individual differences in response to the ads.

As reported in the Journal of Cognitive Neuroscience, they found that strongly persuasive messages simultaneously engage prefrontal areas of the brain responsible for cognitive control and decision-making, and subcortical brain areas important for emotional processing. Ramsay says that they were excited to see the two brain areas working together, as they usually do not interact in a resting state. “This suggests that the experience of being persuaded may represent a special brain state, in which traditionally opponent areas coordinate to synthesize information that is both affectively and cognitively demanding,” he says.

The results suggest that what distinguishes persuasive PSAs from weak ones is their ability to elicit an emotional response while still requiring the viewer to understand the negative consequences of drug use. “These messages had less yelling, but were more compelling,” Ramsay says. “It is our hope that future PSA campaigns can utilize these features to ensure their success.